When I run the following command at shell prompt on Debian or Ubuntu Linux
mdadm -Ac partitions /dev/md0 -m dev
I’m getting the message/warning that read as follows:
Failed to RUN_ARRAY /dev/md0 invalid argument.
How do I fix this issue? How do I rebuild array again on Linux operating system using mdadm command?
This error indicate that the RAID metadata is lost or is no longer consistent. However, sometime following command can fix the issue if other two driver are known to be good. /proc/mdstat file will provide RAID status and make sure RAID is active. Type the following command at a shell prompt to fix this issue:
mdadm -A /dev/md0 -f --update=summaries /dev/sda1 /dev/sdb1
For more information, check out the manual page for mdadm:
$ man mdadm